This bathes deep within the realm of obvious but wear a helmet. As Vietnam is still a developing nation, road etiquette is dissimilar to what you are accustomed to back home. Life on the road is a little more dog-eat-dog here, and you do need to push for position. That doesn’t mean you need to be overly aggressive but do try to hold your ground. Always use your horn to get the attention of others but use it in short bursts. Long bursts are interpreted as arrogant and rude.
Traffic in the major cities could be described as a kind of successful chaos. It seems unpredictable and disorganised, but it adds to the charm of Vietnam, and somehow it works too! Luckily, the major cities are usually too congested for anyone to reach dangerous speeds.
Therefore an accident will most likely leave you with a few bumps and bruises, nothing more. However, take care if you’re heading out of Hanoi or Ho Chi Minh. Not all locals use their indicators so be prepared for unexpected turns. If you are not comfortable with the road culture here, it is best to take a taxi.
Vietnam remains a low-threat country and is relatively safe to visit at any time of year. It is advisable to take note of the standard precautions during the monsoon seasons and when in doubt, do as the locals do. If you are ever feeling under the weather or if you have an accident, there are numerous international hospitals scattered throughout the country.
If you do have an accident, you should either call the emergency number 115 or get yourself to the nearest hospital as soon as possible. For bumps and bruises, public hospitals will be fine on a pay-as-you-go basis, but you will need a local Vietnamese person to help explain your problem. Be warned that international hospitals are expensive and it is strongly recommended that you take out an appropriate insurance policy. Without insurance, your medical expenses could be an extremely bitter pill to swallow! In addition to this, be sure to get yourself vaccinated for Polio, Hepatitis and other nasties before coming to Vietnam.
Source: Expat Blog